2010-12-21

Within Monty Program Ab we have during this year had a lot of discussions about how to go forward with the MariaDB trademark. It's been clear that everyone wants to have something that is substantially freer than the MySQL trademark to ensure the survival of MariaDB whatever happens to Monty Program Ab.

We wanted to make something that should work well, both for open source and commercial usage (and yes, I know that in some cases these are one and the same), which is not very common with many other trademark policies. My belief is that by having a very liberal trademark policy we will create a bigger ecosystem around MariaDB which will help all of us.

2010-12-16

Congratulations to Oracle and the MySQL team for getting 5.5 out the door!

I first have to acknowledge that I have not been able to follow the MySQL 5.5 development as closely as I would have wanted during the last 2 years as most of the planning of MySQL 6.0, 5.4 and 5.5 has happened behind closed doors, without insight for the community. The commits have been open, until recently, but it's not easy to follow what is happening just based on the commits. I am sure that I am missing below some of the important features in 5.5 and forgetting to acknowledge some of the people that have done great work on 5.5.

That said, the 5.5 release contains some things that a lot of heavy users of MySQL have waited a long time for. Here follows some of the main things that I know about.

InnoDB improvements:

The new version 1.1 of the already improved InnoDB plugin is now the default (and only) InnoDB (in 5.1 the InnoDB plugin version 1.0.x was an optional engine).

Multiple buffer pools and rollback segments, splitting of log_sys and flush_list mutex, and other improvements that together give a major contribution to the improved scalability and performance of 5.5.

Thanks to the InnoDB team for continuing to do impressive work!

Adding DDL locking.

In earlier MySQL versions LOCK_open, which protected table opening (among other things), was one of the main things that stopped MySQL from scaling on many CPU's, especially when many tables were used. By introducing proper DDL locking this issue is now mostly fixed.

A big thanks to Konstantin Osipov and Dimitry Lenev for the hard work they have done in getting this to work.

Reducing scalability bottlenecks in the core server, such as LOCK_open, LOCK_alarm, LOCK_thread_count, Query cache and binlog mutexes and so on.

It's now almost exactly 2 years since the MySQL 5.1 GA release, so what's the verdict of 5.5?

The two things that impress me are the work on the InnoDB storage engine and the DLL locking. Most of the other new features are minor (technically) adjustments even if the results, like with the windows speed improvement, can be impressive. As a technical person I have a hard time getting impressed by something that could be done in a few hours and could easily have been done in 5.1.

What is worrying me the most is the things that are not in 5.5. Some if the things that were supposed to be in the next MySQL release are:

Pool of threads (instead of one thread per connection like it is in MySQL 5.1).

As far as I know, this feature has been moved to appear in 5.6 enterprise and will not be part of the community server.

An open source, free backup utility and backup API that would work for all storage engines. This has probably been the most awaited feature of MySQL ever!

This project was discontinued by Oracle the same day the feature was deemed ready to be pushed into 5.5.

In 5.5 some internal subsystems, like safemalloc, a portable memory checker, were removed.

Another worry I have is how long Oracle will be able to continue development of MySQL while important core developers continue to leave. Of the above, Konstantin Osipov and Vladislav Vaintroub have already left Oracle and there are not many old-timers left.

When it comes to MariaDB we are continuing to work making MariaDB 5.3 stable. MariaDB 5.1, 5.2 and 5.3 use the InnoDB-plugin compatible XtraDB storage engine, which already has many of the speed improvements of the new InnoDB plugin, but not yet the windows speed improvement.

We have already merged MariaDB 5.3 with MySQL 5.5 and we will release the MariaDB 5.5 tree shortly. It has taken some time as there are a lot of things done in MariaDB 5.3 that conflict with new code in MySQL 5.5 and we also have to add back some of the features removed in MySQL 5.5.

The next big decision is to decide which version we should release next as a stable release; MariaDB 5.3 or MariaDB 5.5.

The problem is that it's very hard to evaluate how stable 5.5 really is as that 5.5 has not been tested by the public enough and some of the bugs in the public bug system, like the critical Bug #33082, can't be accessed. The bug database shows 294 open bugs for MySQL 5.1 and 150 for MySQL 5.5. I haven't however had time to evaluate all public bugs, so I don't know how severe they really are. A lot depends also how many bugs will be filed during the next few weeks after the GA release.

Note: I corrected the above sentence after getting confirmation that the MySQL team has not yet switched to Oracle's internal bug system. This is scheduled to happen first in the spring. Thanks for helping me get the facts right!

So our plan is to continue to fix the last issues in MariaDB 5.3 and at the same time keep MariaDB 5.5 up to date. Early next year when it's time to decide which one to release as stable, we will have more information about the stability of MySQL 5.5. Let's all hope for the best!

2010-12-14

We have received many requests for a client library for MariaDB (and MySQL) under a license other than the GPL, and decided that it's now time to do something about it.

Some time ago we released the LGPL client library used in MySQL 3.23. This can be used by many applications to connect to MariaDB, MySQL, and Drizzle, but doesn't satisfy all the requirements one would like to see for a true replacement for the current GPL client library.

Minimum requirements are:

It should be binary link level compatible with the current MySQL 5.1 client library. To use it, one would just have to re-link the application with the new library. No re-compilation of the source should be necessary.

It should have all functionality of the MySQL 5.1 client library (including prepared statements).

It should be able to connect to all current versions of MariaDB, MySQL and Drizzle.

It should support all the new functionality in MariaDB's client library like new client functions and pluggable authentication.

The license should be one of BSD/LGPL/Apache.

We have now started to actively plan for getting this done. The plans can be found in our Worklog.

We have already found some companies that are willing to sponsor this project, but not yet enough to get it all done.

If you are willing to donate some time and effort on this, please contact us at'maria-developers at lists.launchpad.com' or 'community at askmonty.org' (we strongly prefer the public maria developers list).

If you are willing to sponsor this effort, please contact us at 'sales at askmonty.org' or use our contact form.

We will put all monetary sponsorship into the Worklog. As with all worklog items, if someone from the community delivers a working solution that is accepted into the MariaDB source they will get 60% of the so far committed money.